This invention relates to a fluid pressure control apparatus including a pair of fluid pressure limiting valves or fluid pressure reducing valves to be used in a brake system of dual-circuit type wherein braking fluid pressure produced in a master cylinder is transmitted through a pair of mutually independent piping circuits to each of the rear wheels, right and left.
A fluid pressure control apparatus in which a pair of valve plungers are disposed parallel to each other in one housing with respective rear end protruding out of the housing and share one biasing device to be biased into the housing is already known by the United Kingdom patent specifications Nos. 1,531,803; 1,557,051; etc.
Parallel plunger type control apparatuses of this kind are all defective in being too complicated in the structure of the biasing device, lacking operational stability, or producing strange noise or getting rid of some parts when the valve is forcibly vibrated as a whole. They have been anyway far from being fully satisfactory.